1. Field of the Invention
The present invention is related to electrooptic modulators.
2. Background Art
In a pattern generating environment that patterns an impinging beam of radiation, which is later projected onto an object, controlling characteristics of the illumination beam of radiation and/or the patterned beam is critical. This is because in order to form accurate patterns on the object, the beam and/or the patterned beam have to be precisely controlled.
Generally, patterning systems use static optical systems, which are typically designed and manufactured for each application in order to produce the light beams with desired characteristics. In the static optical system example, when a change in illumination characteristics is desired or needed, a new optical system must be designed and manufactured, which is costly in terms of money and time. Also, as an output of an illumination source changes with time, this cannot normally be accounted for, which can result in less than desirable results.
In other examples, current methods result in less throughput because corrections are made by throwing away light in areas with unwanted light characteristics and/or because corrections are being performed by relatively slow mechanical devices.
Further, in some examples, by correcting for one optical characteristic, e.g., light intensity uniformity, other characteristics become undesirable, e.g., ellipticity and/or telecentricity.
Therefore, what is needed is a system and method utilizing a dynamic optical system that is adjustable, possibly automatically, in response to measured or detected characteristics of an illumination beam and/or patterned illumination beam, which system and method do not affect throughput during corrections and/or disturb other optical characteristics.